A Dynamic Scheduling Multiagent System for Truck Dispatching in Open-Pit Mines

Material handling is an important process in the mining industry because of its high operational cost. In this process, shovels extract and load materials that must be transported by trucks to different destinations at the mine. When a truck ends an unloading operation, it requires a new loading destination. If a centralized system provides destinations by following dispatching criteria, then one of the main disadvantages of this kind of systems is not being able to provide a precise dispatching solution without knowledge about potentially changed external conditions and the dependency on a central node. In this paper, we describe a distributed approach based on Multiagent Systems (MAS) to alleviate these disadvantages. In this approach, the real-world equipment items such as shovels and trucks are represented by intelligent agents. The agents interact with each other to generate schedules for the machines that they represent. For this interaction, a Contract Net Protocol with a confirmation stage was implemented. In addition, when a machine failure occurs, the agents are able to update their schedules. In order to evaluate the MAS, an agent-based simulation with data from a Chilean open-pit mine was used. The results show that the MAS is able to generate the schedules in a practical computation time-frame. The schedules generated by the MAS decrease the truck cost by 17% on average. Moreover, when a machine failure occurs, the agents are able to repair their schedules in a short period of time.